When we sleep, we give off heat to lower our body temperature. That body heat then gets absorbed by our mattress, sheets, and blankets, which causes many of us to get hot during the night. For some of us who sleep cool, a mattress’ ability to retain our body heat is a plus. For those who sleep hot, mattresses that absorb too much heat are undesirable. If you are one of those people, you want to find a mattress that has good temperature neutrality.
You can always buy a heating or cooling pad to go on top of your mattress to help control your body temperature while you sleep, but there are plenty of mattresses out there that do a good job of keeping you cool without any add-ons.
Innerspring and hybrid mattresses tend to stay cooler, because they are less dense, which allows for greater airflow through the mattress. Many innerspring and hybrid mattresses have gel-infused layers that also help with airflow and temperature control.
Latex is also a very breathable material, so latex beds can be great for those who tend to sleep hot. You get excellent air circulation with a latex bed, which counters the heat your body naturally emits while you sleep.
Memory foam mattresses, being very dense, retain much more of your body heat than other mattress varieties. Those who sleep hot may want to steer clear of memory foam beds for that reason. If you are someone who sleeps hot, but you love the conforming feel of a memory foam bed, there are some that stay cooler than others.